x÷y＝15........9(x丶y均为自然数,且不等于0),x的值最小是

|x-y|=(x−y)2=(x+y)2−4xy．故答案为-4xy．

1.（x-1)^2+2(1-x)=(x-1)(x-1-2)=(x-1)(x-3)2.(x-y)/(x+3y)÷(x^2-y^2)/(x^2+6xy+9y^2)-2y/(x+y）=(x-y)/(x+3y

依题意，得：x2−16≥016−x2≥0，8-2x≠0；即x2-16=0，8-2x≠0；由x2-16=0，得：x=±4；由8-2x≠0，得x≠4；综上知：x=-4；y=−98−2×(−4)=-916；

由题意得x+y＝5mx−y＝9m2x−3y＝9，解得x＝7my＝−2m，代入方程2x-3y=9，解得m=920．故本题答案为：920．

（1）由已知得：x-y=-5，∴9m=-5，∴m=-59，（2）已知方程3x+2y=17与方程组的解相同，所以得：三元一次方程组x+2y＝3mx−y＝9m3x+2y＝17，解得：m=1．

(x+2y)(2x+y)-(3x-y)(x+2y)=(2x^2+5xy+2y^2)-(3x^2+5xy-2y^2)=4y^2-x^2=1-81=-80

原式=-3x^5y³z*x^4y²÷9x^4y^5=-3x^9y^5z÷9x^4y^5=-x^5z/3

[（x+y）2-（x+y）（x+3y）-4y2]÷2y，=[x2+2xy+y2-x2-3xy-xy-3y2-4y2]÷2y=（-2xy-6y2）÷2y=-x-3y，当x=-2，y＝12时，原式=-（-

已知x－y＝1,则y=x-1,x=y+1｛(x＋2y)²＋（2x＋y）(x＋4y)－3(x＋y）（x－y)｝÷y=（x²＋4xy+4y²＋2x²＋9xy+4y&

原式=(x-y)[(x-y)^2-6(x-y)+9]=(x-y)(x-y-3)^2很高兴为您解答,祝你学习进步!不懂可追问!

[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y=[x²-y²-x²-2xy-y²-xy+xy²]/(y/2)=[(x-2)y

方法一：（1）×2-（2）得：3y=3，y=1．将y=1代入（1）得：x+2=6，x=4．∴x+y=1+4=5x+y=5．方法二：两个方程相加，得3x+3y=15，x+y=5．

先一个一个的展开括号项,再同项合并就行了啊[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x=[xx-xy-(xy-yy)+x(x-y)+y(x-y)]÷2x=[xx-xy-xy+yy+xx-

有一个立方和分解因式公式是x³+y³=(x+y）（x²-xy+y²）,所以(x+y)²-（x³+y³)÷（x+y)=(x+y)&s

x平方-6x+9与/y-1/互为相反数(x-3)²+|y-1|=0x-3=0y-1=0x=3y=1(x/y-y/x)÷(x+y)=(3-1/3)÷(3+1)=2/3

[(x-y)/(x+3y)]/[(x^2-y^2)/(x^2+6xy+9y^2)]-xy/(x+y)=(x-y)/(x+3y)*(x+3y)^2/(x-y)(x+y)-xy/(x+y)=(x+3y)/

原式=(x-y)/(x+3y)×[(x+3y)^2/(x+y)(x-y)]-2y/(x+y)=(x+3y)/(x+y)-2y/(x+y)=(x+3y-2y)/(x+y)=(x+y)/(x+y)=1

来个图.再答：感觉好简单再问：额，我在上课再问：再答：再答：可以吗再答：再答：上面还是有个平方。。。再答：懂吗再问：哦哦

((x+y)-(x-y)+2y(x-y)=x+y-(x-2xy+y)+2xy-2y=2xy+2xy-2y=2y(2x-y)=2y×10=20y20y÷4y=5

1.[(x-y)^2-2(y-x)]÷(x-y)=[(x-y)^2+2(x-y)]÷(x-y)=(x-y)(x-y+2)÷(x-y)=x-y+22.[(3a-7)^2-(a+5)^2]÷(4a-24)